PubMed | Federal University of Ouro Preto, Instituto Federal Do Sudeste Of Minas Gerais, Federal University of Viçosa and University of GreifswaldType: Journal Article | Journal: Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] | Year: 2015

The practice of refrigerating raw milk at the farm has provided a selective advantage for psychrotrophic bacteria that produce heat-stable proteases and lipases causing severe quality problems to the dairy industry. In this work, a protease (AprX) and a lipase (LipM) produced by Pseudomonas fluorescens 041, a highly proteolytic and lipolytic strain isolated from raw milk obtained from a Brazilian farm, have been purified and characterized. Both enzymes were purified as recombinant proteins from Escherichia coli . The AprX metalloprotease exhibited activity in a broad temperature range, including refrigeration, with a maximum activity at 37 C. It was active in a pH range of 4.0 to 9.0. This protease had maximum activity with the substrates casein and gelatin in the presence of Ca (+2) . The LipM lipase had a maximum activity at 25 C and a broad pH optimum ranging from 7.0 to 10. It exhibited the highest activity, in the presence of Ca (+2) , on substrates with long-chain fatty acid residues. These results confirm the spoilage potential of strain 041 in milk due to, at least in part, these two enzymes. The work highlights the importance of studies of this kind with strains isolated in Brazil, which has a recent history on the implementation of the cold chain at the dairy farm.

Currently the opportune diagnosis of cancer has shown a great importance, mainly by decreasing the mortality rate. Among the techniques employed to achieve the diagnosis, spectroscopy has been highlighted for presenting safe and highly accurate diagnoses. The Fluorescence Spectroscopy has become very important in cancer diagnosis, being employed in breast, oral cavity and esophagus cancer testing. The technique employs fluorophore which in many cases have groups capable of carrying out the intramolecular proton transfer in the excited state (ESIPT). These compounds may be used for various molecular targets such as cations, anions and proteins detection, besides the diagnosis of diseases. Spectroscopic probes have an important role in the development of more accurate diagnosing diseases methods, which may influence the treatment and avoid the risks of further surgery and patient death.